Tubular interrupter enclosed in bus housing



May 25, 1954 F. L. KRADEL TUBULAR INTERRUPTER ENCLOSED IN BUS HOUSING Filed Feb. 15. 1951 5 Sheets-Sheet l FIG. I.

INVENTOR FEED L. KEADEL ATTORNEYS May 25, 1954 F. L. KRADEL TUBULAR INTERRUPTER ENCLOSED IN BUS HOUSING Filed Feb. 15, 1951 5 Sheets-Sheet 2 INVENTOR F260 LKEADEL BY Y Q MU' ATTORNEYS 5 Sheets-Sheet 3 My NQY hmw H INVENTOR- Y FEFD L. KPADEL QM 9 ATTORNEYS F. L. KRADEL TUBULAR INTERRUPTER ENCLOSED IN BUS HOUSING May 25, 1954 Filed Feb. 15, 1951 y 1954 F. KRADEL 2,679,567

TUBULAR INTERRUPTER ENCLOSED IN BUS HOUSING Fiied Feb. 15, 1951 5 Sheets-Sheet 4 w M f U 7 F. ZiV/ll/ll w fi .w

@M Wm mw. m E

U girl/Wig ATTORN EYS F. L. KRADEL TUBULAR INTERRUPTER ENCLOSED IN BUS HOUSING Filed Feb. 15, 1951 May 25, 1954 5 Sheets-Sheet 5 FIG. 9.

CLOSED UF EN FIG. I'O.

INVENTOR F250 L. KEADl-L @mvw FIGJ l.

ATTO R N EYS Patented May 25, 1954 TUBULAR INTERRUPTER ENCLOSED IN BUS HOUSING Fred L. Kradel, Greensburg, Pa., assignor, by mesne assignments, to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application February 15, 1951, Serial No. 211,133

16 Claims.

My present invention relates to interrupters of the type generally disclosed in Patent No. 2,383,- 795 and more particularly to a tubular interrupter adapted to open a circuit under load and extinguish the are formed during the interruption while at the same time the interrupter is arranged so that all of the interrupting operations, as well as reclosure after interruption, can be accomplished by a single longitudinal motion in appropriate sequence.

More particularly, my invention relates to an interrupter particularly adapted for inclusion in a bus run, preferably in an isolated phase bus enclosure, although, of course, it is adapted for use in segregated phase bus enclosures as well as in connection'with bus runs which are other wise enclosed or not enclosed at all. I

Essentially my novel interrupter comprises a tubular member interconnecting a pair of opposite terminals with the end of the tube. One of the terminals carries a main contact which is circular in cross-section or at least substantially circularly arranged in a plane transverse to the plane of movement of the operating parts of the interrupter.

The movable member of the interrupter has a corresponding circular main contact engaging the stationary main contacts. The stationary contact is essentially all-external contact around the outside of a tube, while the main contact engaging therewith is essentially an internal contact around the periphery of a sliding tube. The stationary contact has in parallel therewith a stationary arcing contact which is also annular and which is mounted on the inside of a tuoe extending from the main stationary contact.

The exterior of the tube extending from the main stationary contact is of insulating mate.

rial, while the interior is of conductive material in :order to establish a connection between the :main stationary contact and the stationary arcing contact.

An arcing contact plunger with an arc extinguishing follower of gas evolving or other appropriate deionizing material is mounted on the in side of the tubular extension from the main stationay contact with means being provided to releas ably iatch the movable arcing contact plunger against movement.

The movable arcing contact plunger is arranged so that on movement away from the main stationary contact of the tube carrying the main movable contact, the movable arcing contact ,plungeris increasingly spring biased toward arcing contact and movable arcing contact, the

are being confined in an annular chamber of small cross-section defined by the follower as the inner wall of the chamber and a tubular are resistant insert as the outer wall of the chamber.

This last operation snaps the plunger back to substantially inside the movable tubular member. During the opening movement of the main contact as well as during the tensioning of the opening bias for the arcing-contact, the movable tubular member hereinbefore described was latched to a second movable tubular member, be ing connected thereto primarily by .a pair of sets of interengaged annularly arranged contacts, the second tubular member being arranged for current carrying connection with the terminal on that side.

Immediately after the plunger for the movable arcing contact is released so that the arc is drawn and the circuit interrupted, the engagement between the contacts of the first-mentioned tubular member and the second-mentioned tubular member is released. Consequently, the opening operation is performed by moving the second-mentioned tubular member away from the main stationary contact, thereby drawing the first-mentioned tubular member with it.

The first step in the operation opens the main contacts but retains the by-pass circuit through the arcing contacts. At the second step in the operation, the arcing contacts open interrupting the circuit.

Immediately after the operation of the latch release mechanism, continued movement of the second-mentioned tubular member results in disengagement of the contacts between the firstmentioned and second-mentioned tubular memher and physical separation of these two members so that further movement of the secondmentioned tubular member in the opening direction serves to create an addtional circuit opening, the circuit in the open condition of the switch being broken at two points in series, one of the points having an air gap between and the other of the points having an insulating sleeve between the opposite contacts.

The primary object of the present invention is the provision of a novel circuit interrupter adapted primarily for use in bus runs.

Another object of the present invention is the provision of a circuit interrupter adapted for inclusion in a bus housing.

Another object of the present invention is the provision of a circuit interrupter which is essentially tubular or longitudinal in construction and operates primarily on longitudinal movement alone.

Another object of the present invention is the provision of a novel arrangement to obtain a plurality of series breaks in the circuit when the circuit interrupter is in the open position.

Another object of the present invention is the provision of novel means for securing together automatically releasing contact elements progressively during the opening movement of the circuit interrupter.

The foregoing and many other objects of my invention will become apparent in the following description and drawings in which:

Figure 1 is a top plan view partly broken away showing the manner in which my novel circuit interrupter may be mounted in isolated phase bus housings for interconnection of longitudinal bus runs.

Figure 2 is a side view of the interrupter of Figure 1 showing the same in closed position, taken on line 22 of Figure 1.

Figure 3 is a side View of the interrupter of Figure 1 showing the same in open circuit position.

Figure 4 is a cross-sectional view taken from line 44 of Figure 2 looking in the direction of the arrows and showing the arrangement of the elements in my novel circuit interrupter in the closed circuit position.

Figure 5 is a view similar to that of Figure 4 showing the intermediate position of my novel circuit interrupter during opening, at which time the arcing contact plunger opening means is being prepared for opening and just prior to the arc interruption.

Figure 6 is a view corresponding to that of Figures 4 and 5 showing the condition immediately after the arc interruption has occurred and just as the operating tube is released from the movable contact tube to create an additional series break in the open circuit condition of my novel circuit interrupter.

Figure 7 is a cross-sectional view taken on line of Figure 4 looking in the direction of the arrows and showing the means for releasing the latching engagement between the second tubular member and the first tubular member and also the method of establishing contact for the by-pass circuit through the arcing contacts.

Figure 8 is a view partly in cross-section taken from line 88 of Figure 1 looking in the direction of the arrows and showing a portion of the opening means for my novel circuit interrupter.

Figure 9 is a cross-sectional view taken from line 99 of Figure 8 looking in the direction of the arrows.

Figure 10 is a cross-sectional view taken on line |ll|0 of Figure 8 looking in the direction of the arrows.

Figure 11 is a cross-sectional view taken on line of Figure 8 looking in the direction of the arrows. v

Referring now particularly to Figure 1 as well as to Figures 2 and 3, my novel circuit interrupter is here shown as a one pole interrupting switch in the isolated phase housing 2| of a bus run (ill 4 comprising isolated phase housings 22, 2| and 23.

It will be obvious that the method of connection here shown will permit the utilization of a two or three or more pole interrupter which is simultaneously operated by the same operating mechanism and for most purposes, of course, the number of poles in the interrupter for simultaneous operation will equal the number of bus runs at the particular location; the description, however, of the operation of one of the poles will sufiice to make clear the operation also of a multipole unit.

The terminal is mounted between insulators 26 and 27, being secured thereto in any suitable fashion, for instance, by bolts 28 passing through extensions 29 of the U-shaped bracket 30 which supports the terminal. Bolts 3| serve to secure the terminal 25 to the base of the U-shaped bracket 30. Insulators 26 and 2'! are supported structurally at their outer ends by the channel beams 32, 32 which serve also to support the walls 33 of the bus enclosure 2|.

Tubular conducting bar 35 is mounted on terminal 25, being rigidly supported at one end by the terminal 25 and the bracket 30. Tubular member is slidably mounted on tubular member 35, the tubular member 40 being the "secondmentioned tubular member hereinbefore referred to before the specific description of the individual figures.

Tubular member 4|) is latched to tubular member 4| in current conducting relation therewith, the said tubular member 4| being the "first-mentioned tubular member hereinabove referred to prior to the specific description of the figures. Tubular member 4| rides over the insulating tube 42 where the contact fingers 43 of the tubular member 4|, in the closed circuit position of the interrupter, engage the annular contact ring 44 which in turn is mounted on U-shaped bracket 30a having a construction and manner of support in the bus enclosure 2| identical with the U-shaped bracket 30 and carrying the opposite terminal 25a which may be connected in any suitable manner as by the pigtail 45 and bar 46 to a bus. Terminal 25 may also be connected in a similar manner to a bus.

Each of the housings 2|, 22, 23 are structurally supported and reinforced by the beams 32. Partitions 40 included in each of the enclosures 2| to 23 to segregate various sections of each isolated phase enclosure and spacer bolts 5| may be provided between adjacent walls of adjacent isolated phase bus enclosures to strengthen the walls and also strengthen the individual buses against deflection owing to magnetic forces which may occur at high currents.

The above referred to second-mentioned sliding tube 40 is supported for sliding movement between rollers 53, 54 carried on insulators 55 and 56. The support for the sliding tube 40 permits the sliding tube 48 itself to support the outer or initially unsupported end of conductor bar 35.

The above referred to first-mentioned sliding tube 4| is similarly supported by rollers and 6| carried, respectively, by insulators 62 and 63, the left-hand end of the sliding tube 4| riding over the insulating tube 42 serving also to support the outer or right-hand end of insulating tube 42 (with respect to Figure 3).

Reference should now be made to Figure 4 as well as to Figures 1, 2, and 3.

It is sufficient for the moment to point out that mechanical means are provided for moving mar-9,567

the "tube 35 in a longitudinal direction toward the rightwith respect to Figures '1 to 4 for the opening movement and to the left with respect to Figures 1 to 4 for theclosing movement and that'the same operating mechanism may be used simultaneously to operate a multi-pole interrupter each individually enclosed in the isolated phase housing of a multi-phase bus.

Terminal 25a as previously pointed out carries the main stationary contact 44 which has an external annular contact surface. The interior of stationary contact 44 is provided with "the annular recess 10 "for retention of garter spring 'II which as hereinafterdescribed. will act.

as the yieldable or releasable latching means for the movable arcing contact plunger.

The recess I communicates with the internally threaded counterbore I3 at the right end of the :main contact 44. Conducting tube 86 having Lthethreaded end BI is screwed into the internally threaded-recess I3, thereby providing a retaining surface I5 for holding the garter spring H in place and providing, of course, a conductive extension for the contact 44.

The right-hand end of conducting tube 80 is provided with an annular recess 83 for retention of the stationary arcing contact 84 and has further or beyond the recess 83 the internal thread 85 into which the threaded end 86 of insulating tube 81 may be screwed as an extension of the conducting tube 80, the left-hand end surface 90 'of the tube 81 forming a retaining flange for the stationary arcing contact 34.

The interior conducting tube 80 adjacent the right-hand end thereof is counterbored to a some- What increased diameter at 92 to receive the insulating tubular insert 93 which is supported between the left-hand annular surface 94 on one side and the stationary arcing contact 84 on the other side. The outermost right-hand end of insulating tube 8'! is externally threaded at 95 to receive and support the nut 96 which is also of insulating material, the nut 96 being provided as seen particularly in Figure 7 with four equally spaced radialopenings'il'f receiving the set screws 38, the set screws 98 extending out beyond the periphery of nut 96 to act as a latch release member to permit separation of the first-mentioned tube 4| and the second-mentioned tube 40 at the end of the opening operation.

The right-hand end of insulating tube 33 be- ,yond the threaded section 95 which supports the nut '96 has secured'thereto in any suitable manner the metallic exhaust sleeve I00 carrying annularly arranged about the right-hand face IBI thereof the Ushaped brushes I02 as seen particularly in Figures 6 and 7.

The U-shaped current carrying brushes I02 serve to conduct the arcing current from the plunger to the tube 40 in the manner herein- .after described.

The'wall of metallic tube I03 is provided with a plurality of circumferential openings having appropriate metallic screens to serve as a flame extinguishing exhaust passage for arc gases when the arc is drawn and extinguished in the manner hereinafter described.

.All of the elements thus far described are stationarily secured tothe main stationary contact 44 and hence to the left-hand terminal 25a. The interior of conducting tube 83 provides a chamber I In which essentially is for the purpose only of receiving the follower IIZ as hereinafter de scribed the chamber III) communicating with the arc'extinguishingchamber II I to'the right of the stationary arcing contact 84 which is formed by the interior wall of insulating tube 81 and the exterior wall of follower II2 which, of course, is of insulating material, the chamber III being, of course, of annular cross-section.

The tube 4| is a conducting tube which is provided with an externally threaded, recess section I243 at the left-hand end. The main movable contact 43 is a cylindrical internally threaded member which is screwed onto the threaded extension I'ZIl to establish a firm current carrying engagement therewith.

The cylindrical member 43 is slotted at I25, I to produce a plurality of contact fingers I 26 having contact buttons I21 at the ends thereof making contact with the main stationary contact 44. The main copper tube 4| is provided with longitudinal slots I30 as shown in the views of Figures 4 to 6 and especially in Figure '7.

Set screws 98 project into the slots I30. The main copper tube 4| is provided also with an auxiliary external stainless steel tube I32 secured to the tube 4| by bolts I33. Between the latch finger tube I32 and the main tube 4| is provided the latch releasing tube I35 having the longitudinal slots I36 which essentially match with longitudinal slots I39 in the main tube 4|.

The external tube I32 is slotted at I40 to produce a plurality of latching fingers I4| each having a latching detent I42 and each having the internal chamfered surface I43. The latch releasing tube I35 is provided with a correspondingly chamfered end I44 so arranged that when the latch finger tube I32 moves to the right with respect to the latch releasing tube I35, the latching fingers I4I will be spread apart.

The second tube 40 is provided with a plurality of contact fingers I defined by longitudinal slots I5I, the contact fingers I56 having contact buttons I52 engaging the series contact member I53 which is a cylindrical member in electrical contact and in threaded relation at I54 with the right-hand end of the main tube 4|.

When tubes 46 and 4| are interconnected and the interrupter switch is closed, it will be seen that latching detents I42 of latching fingers I4I engage the ledges I56 on contact fingers I56 to retain the interlock between tubes 46 and 4|.

During the opening movement, set screw 93 as hereinafter described acts to stop latch releasing tube I35, thereby causing the latch finger tube chamfered surfaces I43 of latch fingers I4| to be drawn over the chamfer I44 on the latch releasing tube 35, releasing the latches as shown in Figure 6 and permitting tube sections 40 and 4| to separate as shown in Figure 3.

The series contact member I53 which, as above pointed out, is a cylindrical unit screwed into theright-hand end of main tube 4| is provided with the central internally threaded support I68 which stationarily secures with respect to contact I53 the operating rod I62 for the movable arcing contact plunger.

Operating rod I62 extends through opening I53 into the sliding cylindrical copper plunger I54,

the said plunger I54 having the internal chamber IE5, the right-hand wall its containing-opening IE3 and a plug It? at the left-hand wall which plug is of copper and carries the movable arcing contact 'Il'El and is also secured by screw Il'I in the insulating follower IIZ.

Compression spring I83 or a plurality of such compression springs as indicated by the addition of compression spring I8.I is mounted inside chamber I of plunger I64 between the wall I66 of chamber I65 and nut I85 secured on the end of operating rod I62.

Follower H2 is provided at its left-hand end with the latching detent I90 engaged by garter spring II in recess I0. In the closed position of the circuit interrupter, current passes from main stationary contact 44 to contact buttons IZI on contact fingers I26 of the main movable contact 43.

Current then passes through the main copper body of tube 4| to the series contact I53 and then through contact fingers I50 at the end of copper tube 40 into the copper tube 40 and then through the additional series contact 200 comprising a plurality of contact fingers 20I to the copper tube 35.

Since copper tube 35 is connected to terminal 25 and main stationary contact 44 is connected to terminal 25a, this current path establishes a full low loss current carrying passage between the two terminals.

When new tube 40 is drawn to the right by the means hereinafter described in order to open the circuit, because of the connection by means of detents I50 and latches I42 between tube 40 and tube 4|, tube 4| is also drawn to the right. This results in the movement of contact I53 to the right since contact I53 is a part of the tube 4 I, thereby maintaining the engagement between contact fingers I50 of tube 40 and contact I53 of tube 4|. This also results in pulling operating rod I62 for plunger I65 to the right.

At the same time, the main contacts 44 and 43 are opened since contact 43 slides to the right with tube 4| while contact 44 is stationary at terminal 25a.

Consequently, the contact buttons 42? of contact fingers I20 of contact 43 slide oii the main contact 44 and over the insulating tube 42.

A current path as seen in Figure 5 is nevertheless maintained at this time between terminal 25a and terminal 25 despite the fact that engagement between contacts 44 and 43 is broken.

Current now passes through the by-pass from the interior contact 44 to the copper tube to the stationary arcing contact 34 to the wall of plunger I65 and from the wall of plunger I through the U-shaped brush I02 to the interior wall of tube 4| and then to the series contact I53, the contact fingers I50, the tube 40, the contact fingers 20 I, the tube 35 to the terminal 25.

This current path existed initially as will be seen from a comparison of Figures i and 5 even when the interrupter was in closed circuit position and, of course, existed in parallel with the principal current path.

However, on the initiation of the opening movement and on separation of contacts 44 and 43, this last-mentioned current path becomes the only current path through the interrupter.

As now the tubes 40 and 4| continue their movement to the right, springs I80 and IBI are continuously compressed and thereby increase the bias to the right on wall I66 of plunger I64 I until the springs I80 and |8| are fully compressed and now act as a solid bar.

At this time, continued opening movement to the right of tube 40 pulling on tube 4| through rod I62 pulls the chamber I04 to the right and snaps the latching detent I90 of the follower ||2 out from the latching garter spring II to permit an extremely rapid opening movement to the right of plunger I54 and the follower I :2.

As the movable arcing contact I'I0 passes the stationary arcing contact 84, an arc is drawn 8 I between them and extinguished. in the narrow annular passage III between the tube 81 and follower II2, this annular passage being substantially just enough to provide for mechanical clearance between follower H2 and tube 81 and providing an efficient arc extinguishing medium.

Any exhaust gases may now exit through the wall-of the screened tube I00 as previously mentioned.

Just after this opening movement of the arcing contact occurs, on further slight continuation of movement of tube 40 to the right pulling along tube 4|, the slot I30 in intermediate release tube I35 moves to a position where its end abuts against set screw 98.

As previously mentioned, there are a plurality of such set screws and hence a plurality of such slots. This abutment of the left-hand end of slot I35 in intermediate tube I35 against the set screw 98 causes the intermediate tube I35 to move to the left with respect to the main tube 4| as seen by a comparison of Figures 5 and 6 and notably an examination of the difference in clearance at point 2I0 of Figure 5 and 2|0a of Figure 6.

Actually, of course, the tube I35 is caused to remain stationary by the set screw 98 with the insulating tube 42, but the net effect is to cause a movement to the left with respect to the main tube 4| which at the moment is moving to the right. This pulls the chamfered surface wedgeshaped latch releasing annular section I44 against the chambered surface I43 of latch fingers |4| releasing the latching detents I42 from the latching detents I56 on the contact fingers I50 and now permitting the tube 40 to move further to the right clear of tube 4| as shown in Figure 3 to provide an additional series separation for the circuit.

Thus, in moving from the closed to the open position, first the main contacts separate. Second, the arcing contact is tensioned for rapid opening (see Figure 5). Third, the arcing contacts separate (see Figure 6), and immediately after the circuit is additionally broken in series across an air gap by separation of contacts I53 and I50.

In order to close the circuit, tube 40 is driven to the left. The ends of contact fingers I50 strike against the end of tube 4|, pushing it to the left. The end of nut I60 pushes against wall I66 of chamber I64 pushing it to the left and hence pushing the follower II2 to the left so that there is a solid force behind the follower I I2, thereby serving to drive the chamfered surface 200 at the end of the follower in a direction to spread the garter spring II and permit it to engage in the latching detent I 90.

At the same time, of course, movement of tube 4| to the left results in interengagement of contacts 43 and 44.

It is obvious that any suitable means may be provided for operating the tubular interrupter of the present invention and that essentially such means must be arranged so that it will provide a simplified mechanical means for driving tube 40 alone to the left for closing and to the right for opening, the operation of tube 40 alone causing all of the other elements to operate as above described.

Consequently, in Figure 1 (see also Figures 2 and 3) as well'as in Figure 8 I have shown one method of achieving this result.

Tube 40 is provided with a pair of bracket arms 300 secured in any suitable manner thereto and 9. carrying the bracket 30!. Pinion 302 mounted on. shaft 303 will move the rack 30l back. and. forth. and hence tube 40 back and forth in accordance with rotation of shaft 302.

Shaft. 302 is supported between rotatable in.- sulators 305, 300" supported in turn in the side walls of a bus housing or enclosure. Insulator 305. is-connected by coupling 3%! to an appropriate insulated shaft 368 or to another pair ofrotatable-insulatorsin series-in housing 2-2: which in turnare rotatably-connected to shaft.3l0, the essential elementbeingthatshaft 303 be broken into insulated or electrically isolated sections so that no current carrying path for grounding or short circuiting the device will exist along the shaftv 333:.

The composite shaft-303, 305-3) is connected. by bevel gear 312.. to bevel-gear 313-011 shaft 3M which in turn. is connected. by bevel gears 31% and'3ll to shaft 31'8- wh;ch inturn is connected by bevel gears 3.19 and 320 to-crank shafttiit having thecrank-handle 32 4.

Rotation of the crank; handlev 324 in one di.--

motion will rotate the various shafts in a cor.- responding direction to move the interrupter to the openposition and reverse rotation will rotate the shafts in a corresponding direction to-move the. interrupter to the closed position.

The shafts. 313,. 323 are carried. in a suitable housing having a frontwall 33! and a back wall 33m provided with appropriate lugs 332 for securement to appropriate support. Shaft 3 ill has a pair of collars 330 340 secured thereto having a plurality of 'spacedopenings. 3 H andperipheral recesses. 342 asseenin Figures 8 and 9.

A stop member 345=is carriedby the back wall 33l'a of' the machine, the stop member having slidably supported thereon the slide bar 345. The slide bar 346 is anextension of nut. 348 mounted on threaded section 349 of shaft 318; Rotation ofshaft 3|8 causes the nut 348to move longitudinally of shaft 3| Bowing tothe fact that the interengagement of slide 34 3-with. bar 34 5- prevents rotation thereof.

A forward extension 340 of nut 348' carries a pointer 35] which is sliclable through window 352 (seeFigures 8 and to indicatethe-open and closed position. of the interrupter. Set screws 34'|a,.34ila locked inopenings 3-41 of collars 340 on oppositesid'es of the slide bar 343 serve topadlock 315 may be slipped through registering openings as seen in Figures 8 and 11 to maintain the interrupter inthe open or. closed position as the case may be against unauthorizedtampering.

In. the. foregoing I. have described myinvention solely in connection with specific illustrativeembodiments thereof; Since many variations and. modifications .of my invention will now be obvious to those skilled in the art, I prefer to be bound not by the specific disclosures herein contained but only by the appended claims.

Ilclaimi 1. Switch gear extendihglongitudinally along. a principal. axis .and comprising a movable main. contact,. a. movable arcing. contact, a.- movable. disconnect contact and. complementary contacts 1Q forv each of s'aid..movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contactswhen in closed position, a latch for said arcing contacts andbiasingmeans operative following release of said latch for operating said arcing contacts to open position at high speed.

2. Switch gear extending longitudinally along principal axis and comprising amovable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of movable contacts; said movable contacts beingoperable along saidprincipal axis; said movable contacts being operable from closed to open positionv in a predetermined sequence with the main contactopening first, the arcing contact opening next and the disconnect contact opening last, a latch for said arcing contacts and biasing. means rendered effective to release said latch and operate saidcontacts to open position at high speed.

3. Switch gear extending longitudinally along a principal axis and comprising a movablemain contact, a movable arcing contact, a movable disconnect contact and complementary contacts for eachof said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series. with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in. a predetermined sequence with the main contact opening first, the arcing contact opening next and the disconnect contact opening last, and biasing means connected to said arcing contacts and operative to provide snap action for opening of said arcing contacts.

4. Switch gear extending longitudinally along a principal axis and comprising-a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contactsbeing in parallel when in closed position, said disconnect contact being inseries with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence with the main contact opening first, the. arcing contact opening next and the disconnect contact opening last, and an arc extinguishing chamber extending longitudinally along saidprincipal axis, and biasing means connected to said arcing contact and operative to provide'high speed opening of said arcing contact.

5. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable alongsaid principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main'and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined'sequence with the main contact opening first, the arcin contact opening next and the disconnect contact opening last, and an arc extinguishin chamber extending longitudinally along said principal axis, and an 11 insulating follower extending from said arcing contact through said are extinguishing chamber alon said principal axis.

6. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence with the main contact openin first, the arcing contact opening next and the disconnect contact opening last, and an arc extinguishing chamber extending longitudinally alon said principal axis, an insulating follower extending from said arcing contact through said arc extinguishing chamber along said principal axis, and a member carrying said main movable contact; said member housing said arcing contacts and arc extinguishing chamber.

7. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable con-- tacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open posi tion in a predetermined sequence with the main contact opening first, the arcing contact opening next and the disconnect contact opening last, and an arc extinguishing chamber extending longitudinally along said principal axis, an insulating follower extending from said arcing contact through said are extinguishing chamber along said principal axis, and a member carrying said main movable contact, said member housing said arcing contacts and are extinguishing chamber, said movable disconnect contact when engaged with its complementary contact being in latched engagement with said last-mentioned member; the complementary contact for the disconnect contact being mounted on said member.

8. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact bein in series with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence with the main contact opening first, the arcing contact opening next and the disconnect contact openin last, and an arc extinguishing chamber extending longitudinally along said principal axis, an insulating follower extending from said arcing contact through said are extinguishing chamber along said principal axis, a member carrying said main movable contact, said member having its main axis coinciding with said principal axis; said member housing said arcing contacts and are extinguishing chamber, said movable disconnect contact when engaged with its complementary contact being in latched engagement with said last-mentioned member; the complementary contact for the disconnect contact being mounted on said member; and operating mechanism connected to and movin said movable disconnect contact and being operable through said latch mechanism to draw said last-mentioned member toward open circuit position at said main contacts.

9. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence wtih the main contact opening first, the arcing contact opening next and the disconnect contact opening last, and an arc extinguishing chamber extending longitudinally along said principal axis, an insulating follower extending from said arcing contact through said are extinguishing chamber along said principal axis, a member carrying said main movable contact, said member having its main axis coinciding with said principal axis; said member housing said arcing contacts and arc extinguishing chamber, said movable disconnect contact when engaged with its complementary contact being in latched engagement with said last-mentioned member; the complementary contact for the disconnect contact being mounted on said member; operating mechanism connected to and moving said movable disconnect contact and being operable through said latch mechanism to draw said last-mentioned member toward open circuit position at said main contacts; and means at said complementary main contact for retaining said movable arcing contact stationary while said member is drawn toward open circuit position at said main contact and maintaining said arcing contacts in engagement.

10. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence with the main contact opening first, the arcing contact opening next and the disconnect contact opening last, and an arc extinguishing chamber extending longitudinally along said principal axis, an insulating follower extending from said arcing contact through said arc extinguishing chamber along said principal axis, a member carrying said main movable contact; said member housing said arcing contacts and are extinguishing chamber, said movable disconnect contact when engaged with its complementary contact being in latched engagement with said last-mentioned member; the complementary contact for the disconnect contact being mounted on said member; operating mechanism connected to and moving said movable disconnect contact and being operable through said latch mechanism to draw said lastis mentioned member toward" open circuit positionatsaid main contacts; means at said complementary maincontact for retaining said movable arcing contact stationary while said member is drawn toward open circuit position at said main contact and maintainingsaid arcing contacts in engagement; and a resilient energy storing connection between said movable arcing contact and said member; said energy storing connection being biased to increase" the opening force on; the movable arcing contact as the member is moved further toward open circuit position.

1 1-. Switch gear extending l'cng-i'tudially along a principal axis and comprising a movable main contact, a movable arcing contact, a movable: disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being parallel when in closed position, said disconnect-contact being in series: with said main. and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence with themain contact opening first, the arcing contact opening next and the disconnect contact. openlast, and an arc extinguishing chamber extending longitudinally along said principal: axis,

mentary contact. for the. disconnect:- contact: being mounted on said member; operating mechanism connected to and moving said movable disconnect contact and being operable through said latch mechanism to draw said last-mentioned member toward open circuit position at said main contacts; means at said complementary main contact for retaining said movable arcing contact stationary while said member is drawn toward open circuit position at said main contact and maintaining said arcing contacts in engagement; and a resilient energy storing connection between said movable arcing contact and said member; said energy storing connection being biased to increase the opening force on the movable arcing contact as the member is moved further toward open circuit position; said energy storing connection disengaging said arcing contact retaining means at the completion of movement of said member and driving said arcing contact out of engagement with its main contact.

12. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence with the main contact opening first, the arcing contact opening next and the disconnect contact opening last, and an arc extinguishing chamber extending longitudinally along said principal 14. axis, an insulating follower: extending from-saidarcing contact through said arc extinguishing; chamber along said principal axis, a membercarrying said main movable contact, said member having. its main axis; coinciding with said principal axis; said member housing said arcing contacts and. are extinguishing chamber, said movable disconnect contact when engaged with its complementary contact. being in latched engagement with said last-mentioned member; the complementary contact. for the disconnect contact being mounted on said member; operating mechanism connected to: and moving said movable disconnect contact and being through said latch mechanism to draw said. lastmentioned member toward open circuit position at said main. contacts; means at said complementary main contact for retaining said movable arcing contact stationary while. said member is drawn. toward open circuit position at said main contact. and maintaining. said arcing contacts in engagement; a, resilient energy storing. connection between said movable arcing contact. and said member; said energy storing connection being. biased to increase the opening force on the movable arcing contact. as. the member is moved further toward open circuit position; said energy storing connection disengaging said arcing contact retaining means at. the completion of movement of said member and. driving said arcing contact out of engagement with its main contact, and a latch releasing element; said movable arcing contact operating said latch releasing element on completion of opening movement of said arcing contact.

13. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing. contact, a movable. disconnect contact and complementary contacts. for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contacts when in closed position; said movable contacts being operable from closed to open position in a predetermined sequence with the main contact opening first, the arcing contact opening next and the disconnect contact opening last, and an arc extinguishing chamber extending longitudinally along said principal axis, an insulating follower extending from said arcing contact through said arc extinguishing chamber along said principal axis, a member carrying said main movable contact, said member having its main axis coinciding with said principal axis; said member housing said arcing contacts and are extinguishing chamber, said movable disconnect contact when engaged with its complementary contact being in latched engagement with said last-mentioned member; the complementary contact for the disconnect contact being mounted on said member; operating mechanism connected to and moving said movable disconnect contact and being operable through said latch mechanism to draw said last-mentioned member toward open circuit position at said main contacts; means at said complementary main contact for retaining said movable arcing contact stationary while said member is drawn toward open circuit position at said main contact and maintaining said arcing contacts in engagement; a resilient energy storing connection between said movable arcing contact and said member,- said energy storing connection being biased operable.

to increase the opening force on the movable arcing contact as the member is moved further toward open circuit position; said energy storing connection disengaging said arcing contact retaining means at the completion of movement of said member and driving said arcing contact out of engagement with its main contact, and a latch releasing I element; contact operating said latch releasing element on completion of opening movement of said arcing contact, said operating mechanism thereafter drawing said disconnect contact away from its complementary contact while said member remains stationary in the open circuit position.

14. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; operating mechanism, a member carrying said movable main and arcing contacts; a. movable disconnect contact unit carrying said movable disconnect contact;'t-he complementary disconnect contact being carried by said member; said operating mechanism being connected to and operating said movable disconnect contact unit; and a latch connection between said movable disconnect contact unit and said member.

15. Switch gear extending longitudinally along said movable arcing nect contact being carried by said member; said operating mechanism being connected to and operating said movable disconnect contact unit; a latch connection between said movable disconnect contact unit and said member; and means releasing said latch connection upon opening movement of said arcing contact.

16. Switch gear extending longitudinally along a principal axis and comprising a movable main contact, a movable arcing contact, a movable disconnect contact and complementary contacts for each of said movable contacts; said movable contacts being operable along said principal axis; said main contacts and arcing contacts being in parallel when in closed position, said disconnect contact being in series with said main and arcing contacts when in closed position; said movable contacts being operable from open to closed position in a predetermined sequence, the disconnect contacts closing first, the arcing contacts and the main contacts closing thereafter, and an arc extinguishing chamber extending longitudinally along said principal axis, an insulating follower extending from said arcing contact through said arc extinguishing chamber along said principal axis, a member carrying said main movable contact; said member housing said arcing contacts and arc extinguishing chamber.

References Cited in the file Of this patent UNITED STATES PATENTS Number Name Date 2,164,175 Frank June 27, 1939 2,203,863 Farrell June 11, 1940 2,306,242 Bartlett Dec. 22, 1942 2,434,315 Froland Jan. 13, 1948 2,445,588 Skeats July 20, 1948 2,462,285 Rees Feb. 22, 1949 

